1 files changed, 236 insertions, 194 deletions

diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 32b4a1675d82..5e1da088d8e1 100644
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * INET		An implementation of the TCP/IP protocol suite for the LINUX
  *		operating system.  INET is implemented using the BSD Socket
@@ -6,58 +7,38 @@
  *		Generic INET6 transport hashtables
  *
  * Authors:	Lotsa people, from code originally in tcp, generalised here
- * 		by Arnaldo Carvalho de Melo <acme@mandriva.com>
- *
- *	This program is free software; you can redistribute it and/or
- *      modify it under the terms of the GNU General Public License
- *      as published by the Free Software Foundation; either version
- *      2 of the License, or (at your option) any later version.
+ *		by Arnaldo Carvalho de Melo <acme@mandriva.com>
  */
 
 #include <linux/module.h>
 #include <linux/random.h>
 
+#include <net/addrconf.h>
+#include <net/hotdata.h>
 #include <net/inet_connection_sock.h>
 #include <net/inet_hashtables.h>
 #include <net/inet6_hashtables.h>
 #include <net/secure_seq.h>
 #include <net/ip.h>
+#include <net/sock_reuseport.h>
+#include <net/tcp.h>
 
-int __inet6_hash(struct sock *sk, struct inet_timewait_sock *tw)
+u32 inet6_ehashfn(const struct net *net,
+		  const struct in6_addr *laddr, const u16 lport,
+		  const struct in6_addr *faddr, const __be16 fport)
 {
-	struct inet_hashinfo *hashinfo = sk->sk_prot->h.hashinfo;
-	int twrefcnt = 0;
+	u32 lhash, fhash;
 
-	WARN_ON(!sk_unhashed(sk));
+	net_get_random_once(&inet6_ehash_secret, sizeof(inet6_ehash_secret));
+	net_get_random_once(&tcp_ipv6_hash_secret, sizeof(tcp_ipv6_hash_secret));
 
-	if (sk->sk_state == TCP_LISTEN) {
-		struct inet_listen_hashbucket *ilb;
-
-		ilb = &hashinfo->listening_hash[inet_sk_listen_hashfn(sk)];
-		spin_lock(&ilb->lock);
-		__sk_nulls_add_node_rcu(sk, &ilb->head);
-		spin_unlock(&ilb->lock);
-	} else {
-		unsigned int hash;
-		struct hlist_nulls_head *list;
-		spinlock_t *lock;
-
-		sk->sk_hash = hash = inet6_sk_ehashfn(sk);
-		list = &inet_ehash_bucket(hashinfo, hash)->chain;
-		lock = inet_ehash_lockp(hashinfo, hash);
-		spin_lock(lock);
-		__sk_nulls_add_node_rcu(sk, list);
-		if (tw) {
-			WARN_ON(sk->sk_hash != tw->tw_hash);
-			twrefcnt = inet_twsk_unhash(tw);
-		}
-		spin_unlock(lock);
-	}
+	lhash = (__force u32)laddr->s6_addr32[3];
+	fhash = __ipv6_addr_jhash(faddr, tcp_ipv6_hash_secret);
 
-	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
-	return twrefcnt;
+	return lport + __inet6_ehashfn(lhash, 0, fhash, fport,
+				       inet6_ehash_secret + net_hash_mix(net));
 }
-EXPORT_SYMBOL(__inet6_hash);
+EXPORT_SYMBOL_GPL(inet6_ehashfn);
 
 /*
  * Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
@@ -65,242 +46,292 @@ EXPORT_SYMBOL(__inet6_hash);
  *
  * The sockhash lock must be held as a reader here.
  */
-struct sock *__inet6_lookup_established(struct net *net,
-					struct inet_hashinfo *hashinfo,
-					   const struct in6_addr *saddr,
-					   const __be16 sport,
-					   const struct in6_addr *daddr,
-					   const u16 hnum,
-					   const int dif)
+struct sock *__inet6_lookup_established(const struct net *net,
+					const struct in6_addr *saddr,
+					const __be16 sport,
+					const struct in6_addr *daddr,
+					const u16 hnum,
+					const int dif, const int sdif)
 {
-	struct sock *sk;
-	const struct hlist_nulls_node *node;
 	const __portpair ports = INET_COMBINED_PORTS(sport, hnum);
-	/* Optimize here for direct hit, only listening connections can
-	 * have wildcards anyways.
-	 */
-	unsigned int hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
-	unsigned int slot = hash & hashinfo->ehash_mask;
-	struct inet_ehash_bucket *head = &hashinfo->ehash[slot];
-
+	const struct hlist_nulls_node *node;
+	struct inet_ehash_bucket *head;
+	struct inet_hashinfo *hashinfo;
+	unsigned int hash, slot;
+	struct sock *sk;
 
-	rcu_read_lock();
+	hashinfo = net->ipv4.tcp_death_row.hashinfo;
+	hash = inet6_ehashfn(net, daddr, hnum, saddr, sport);
+	slot = hash & hashinfo->ehash_mask;
+	head = &hashinfo->ehash[slot];
 begin:
 	sk_nulls_for_each_rcu(sk, node, &head->chain) {
 		if (sk->sk_hash != hash)
 			continue;
-		if (likely(INET6_MATCH(sk, net, saddr, daddr, ports, dif))) {
-			if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt)))
-				goto begintw;
-			if (unlikely(!INET6_MATCH(sk, net, saddr, daddr,
-						  ports, dif))) {
-				sock_put(sk);
-				goto begin;
-			}
-		goto out;
-		}
-	}
-	if (get_nulls_value(node) != slot)
-		goto begin;
-
-begintw:
-	/* Must check for a TIME_WAIT'er before going to listener hash. */
-	sk_nulls_for_each_rcu(sk, node, &head->twchain) {
-		if (sk->sk_hash != hash)
+		if (!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))
 			continue;
-		if (likely(INET6_TW_MATCH(sk, net, saddr, daddr,
-					  ports, dif))) {
-			if (unlikely(!atomic_inc_not_zero(&sk->sk_refcnt))) {
-				sk = NULL;
-				goto out;
-			}
-			if (unlikely(!INET6_TW_MATCH(sk, net, saddr, daddr,
-						     ports, dif))) {
-				sock_put(sk);
-				goto begintw;
-			}
+		if (unlikely(!refcount_inc_not_zero(&sk->sk_refcnt)))
 			goto out;
+
+		if (unlikely(!inet6_match(net, sk, saddr, daddr, ports, dif, sdif))) {
+			sock_gen_put(sk);
+			goto begin;
 		}
+		goto found;
 	}
 	if (get_nulls_value(node) != slot)
-		goto begintw;
-	sk = NULL;
+		goto begin;
 out:
-	rcu_read_unlock();
+	sk = NULL;
+found:
 	return sk;
 }
 EXPORT_SYMBOL(__inet6_lookup_established);
 
-static inline int compute_score(struct sock *sk, struct net *net,
+static inline int compute_score(struct sock *sk, const struct net *net,
 				const unsigned short hnum,
 				const struct in6_addr *daddr,
-				const int dif)
+				const int dif, const int sdif)
 {
 	int score = -1;
 
 	if (net_eq(sock_net(sk), net) && inet_sk(sk)->inet_num == hnum &&
 	    sk->sk_family == PF_INET6) {
-		const struct ipv6_pinfo *np = inet6_sk(sk);
+		if (!ipv6_addr_equal(&sk->sk_v6_rcv_saddr, daddr))
+			return -1;
 
-		score = 1;
-		if (!ipv6_addr_any(&np->rcv_saddr)) {
-			if (!ipv6_addr_equal(&np->rcv_saddr, daddr))
-				return -1;
-			score++;
-		}
-		if (sk->sk_bound_dev_if) {
-			if (sk->sk_bound_dev_if != dif)
-				return -1;
+		if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
+			return -1;
+
+		score =  sk->sk_bound_dev_if ? 2 : 1;
+		if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
 			score++;
-		}
 	}
 	return score;
 }
 
-struct sock *inet6_lookup_listener(struct net *net,
-		struct inet_hashinfo *hashinfo, const struct in6_addr *saddr,
+/**
+ * inet6_lookup_reuseport() - execute reuseport logic on AF_INET6 socket if necessary.
+ * @net: network namespace.
+ * @sk: AF_INET6 socket, must be in TCP_LISTEN state for TCP or TCP_CLOSE for UDP.
+ * @skb: context for a potential SK_REUSEPORT program.
+ * @doff: header offset.
+ * @saddr: source address.
+ * @sport: source port.
+ * @daddr: destination address.
+ * @hnum: destination port in host byte order.
+ * @ehashfn: hash function used to generate the fallback hash.
+ *
+ * Return: NULL if sk doesn't have SO_REUSEPORT set, otherwise a pointer to
+ *         the selected sock or an error.
+ */
+struct sock *inet6_lookup_reuseport(const struct net *net, struct sock *sk,
+				    struct sk_buff *skb, int doff,
+				    const struct in6_addr *saddr,
+				    __be16 sport,
+				    const struct in6_addr *daddr,
+				    unsigned short hnum,
+				    inet6_ehashfn_t *ehashfn)
+{
+	struct sock *reuse_sk = NULL;
+	u32 phash;
+
+	if (sk->sk_reuseport) {
+		phash = INDIRECT_CALL_INET(ehashfn, udp6_ehashfn, inet6_ehashfn,
+					   net, daddr, hnum, saddr, sport);
+		reuse_sk = reuseport_select_sock(sk, phash, skb, doff);
+	}
+	return reuse_sk;
+}
+EXPORT_SYMBOL_GPL(inet6_lookup_reuseport);
+
+/* called with rcu_read_lock() */
+static struct sock *inet6_lhash2_lookup(const struct net *net,
+		struct inet_listen_hashbucket *ilb2,
+		struct sk_buff *skb, int doff,
+		const struct in6_addr *saddr,
 		const __be16 sport, const struct in6_addr *daddr,
-		const unsigned short hnum, const int dif)
+		const unsigned short hnum, const int dif, const int sdif)
 {
-	struct sock *sk;
-	const struct hlist_nulls_node *node;
-	struct sock *result;
-	int score, hiscore, matches = 0, reuseport = 0;
-	u32 phash = 0;
-	unsigned int hash = inet_lhashfn(net, hnum);
-	struct inet_listen_hashbucket *ilb = &hashinfo->listening_hash[hash];
+	struct sock *sk, *result = NULL;
+	struct hlist_nulls_node *node;
+	int score, hiscore = 0;
 
-	rcu_read_lock();
-begin:
-	result = NULL;
-	hiscore = 0;
-	sk_nulls_for_each(sk, node, &ilb->head) {
-		score = compute_score(sk, net, hnum, daddr, dif);
+	sk_nulls_for_each_rcu(sk, node, &ilb2->nulls_head) {
+		score = compute_score(sk, net, hnum, daddr, dif, sdif);
 		if (score > hiscore) {
-			hiscore = score;
+			result = inet6_lookup_reuseport(net, sk, skb, doff,
+							saddr, sport, daddr, hnum, inet6_ehashfn);
+			if (result)
+				return result;
+
 			result = sk;
-			reuseport = sk->sk_reuseport;
-			if (reuseport) {
-				phash = inet6_ehashfn(net, daddr, hnum,
-						      saddr, sport);
-				matches = 1;
-			}
-		} else if (score == hiscore && reuseport) {
-			matches++;
-			if (((u64)phash * matches) >> 32 == 0)
-				result = sk;
-			phash = next_pseudo_random32(phash);
-		}
-	}
-	/*
-	 * if the nulls value we got at the end of this lookup is
-	 * not the expected one, we must restart lookup.
-	 * We probably met an item that was moved to another chain.
-	 */
-	if (get_nulls_value(node) != hash + LISTENING_NULLS_BASE)
-		goto begin;
-	if (result) {
-		if (unlikely(!atomic_inc_not_zero(&result->sk_refcnt)))
-			result = NULL;
-		else if (unlikely(compute_score(result, net, hnum, daddr,
-				  dif) < hiscore)) {
-			sock_put(result);
-			goto begin;
+			hiscore = score;
 		}
 	}
-	rcu_read_unlock();
+
 	return result;
 }
 
+struct sock *inet6_lookup_run_sk_lookup(const struct net *net,
+					int protocol,
+					struct sk_buff *skb, int doff,
+					const struct in6_addr *saddr,
+					const __be16 sport,
+					const struct in6_addr *daddr,
+					const u16 hnum, const int dif,
+					inet6_ehashfn_t *ehashfn)
+{
+	struct sock *sk, *reuse_sk;
+	bool no_reuseport;
+
+	no_reuseport = bpf_sk_lookup_run_v6(net, protocol, saddr, sport,
+					    daddr, hnum, dif, &sk);
+	if (no_reuseport || IS_ERR_OR_NULL(sk))
+		return sk;
+
+	reuse_sk = inet6_lookup_reuseport(net, sk, skb, doff,
+					  saddr, sport, daddr, hnum, ehashfn);
+	if (reuse_sk)
+		sk = reuse_sk;
+	return sk;
+}
+EXPORT_SYMBOL_GPL(inet6_lookup_run_sk_lookup);
+
+struct sock *inet6_lookup_listener(const struct net *net,
+				   struct sk_buff *skb, int doff,
+				   const struct in6_addr *saddr,
+				   const __be16 sport,
+				   const struct in6_addr *daddr,
+				   const unsigned short hnum,
+				   const int dif, const int sdif)
+{
+	struct inet_listen_hashbucket *ilb2;
+	struct inet_hashinfo *hashinfo;
+	struct sock *result = NULL;
+	unsigned int hash2;
+
+	/* Lookup redirect from BPF */
+	if (static_branch_unlikely(&bpf_sk_lookup_enabled)) {
+		result = inet6_lookup_run_sk_lookup(net, IPPROTO_TCP, skb, doff,
+						    saddr, sport, daddr, hnum, dif,
+						    inet6_ehashfn);
+		if (result)
+			goto done;
+	}
+
+	hashinfo = net->ipv4.tcp_death_row.hashinfo;
+	hash2 = ipv6_portaddr_hash(net, daddr, hnum);
+	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
+
+	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
+				     saddr, sport, daddr, hnum,
+				     dif, sdif);
+	if (result)
+		goto done;
+
+	/* Lookup lhash2 with in6addr_any */
+	hash2 = ipv6_portaddr_hash(net, &in6addr_any, hnum);
+	ilb2 = inet_lhash2_bucket(hashinfo, hash2);
+
+	result = inet6_lhash2_lookup(net, ilb2, skb, doff,
+				     saddr, sport, &in6addr_any, hnum,
+				     dif, sdif);
+done:
+	if (IS_ERR(result))
+		return NULL;
+	return result;
+}
 EXPORT_SYMBOL_GPL(inet6_lookup_listener);
 
-struct sock *inet6_lookup(struct net *net, struct inet_hashinfo *hashinfo,
+struct sock *inet6_lookup(const struct net *net,
+			  struct sk_buff *skb, int doff,
 			  const struct in6_addr *saddr, const __be16 sport,
 			  const struct in6_addr *daddr, const __be16 dport,
 			  const int dif)
 {
 	struct sock *sk;
+	bool refcounted;
 
-	local_bh_disable();
-	sk = __inet6_lookup(net, hashinfo, saddr, sport, daddr, ntohs(dport), dif);
-	local_bh_enable();
-
+	sk = __inet6_lookup(net, skb, doff, saddr, sport, daddr,
+			    ntohs(dport), dif, 0, &refcounted);
+	if (sk && !refcounted && !refcount_inc_not_zero(&sk->sk_refcnt))
+		sk = NULL;
 	return sk;
 }
-
 EXPORT_SYMBOL_GPL(inet6_lookup);
 
 static int __inet6_check_established(struct inet_timewait_death_row *death_row,
 				     struct sock *sk, const __u16 lport,
-				     struct inet_timewait_sock **twp)
+				     struct inet_timewait_sock **twp,
+				     bool rcu_lookup,
+				     u32 hash)
 {
 	struct inet_hashinfo *hinfo = death_row->hashinfo;
 	struct inet_sock *inet = inet_sk(sk);
-	const struct ipv6_pinfo *np = inet6_sk(sk);
-	const struct in6_addr *daddr = &np->rcv_saddr;
-	const struct in6_addr *saddr = &np->daddr;
+	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
+	const struct in6_addr *saddr = &sk->sk_v6_daddr;
 	const int dif = sk->sk_bound_dev_if;
-	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 	struct net *net = sock_net(sk);
-	const unsigned int hash = inet6_ehashfn(net, daddr, lport, saddr,
-						inet->inet_dport);
+	const int sdif = l3mdev_master_ifindex_by_index(net, dif);
+	const __portpair ports = INET_COMBINED_PORTS(inet->inet_dport, lport);
 	struct inet_ehash_bucket *head = inet_ehash_bucket(hinfo, hash);
-	spinlock_t *lock = inet_ehash_lockp(hinfo, hash);
-	struct sock *sk2;
+	struct inet_timewait_sock *tw = NULL;
 	const struct hlist_nulls_node *node;
-	struct inet_timewait_sock *tw;
-	int twrefcnt = 0;
-
-	spin_lock(lock);
-
-	/* Check TIME-WAIT sockets first. */
-	sk_nulls_for_each(sk2, node, &head->twchain) {
-		if (sk2->sk_hash != hash)
-			continue;
-
-		if (likely(INET6_TW_MATCH(sk2, net, saddr, daddr,
-					  ports, dif))) {
-			tw = inet_twsk(sk2);
-			if (twsk_unique(sk, sk2, twp))
-				goto unique;
-			else
-				goto not_unique;
+	struct sock *sk2;
+	spinlock_t *lock;
+
+	if (rcu_lookup) {
+		sk_nulls_for_each(sk2, node, &head->chain) {
+			if (sk2->sk_hash != hash ||
+			    !inet6_match(net, sk2, saddr, daddr,
+					 ports, dif, sdif))
+				continue;
+			if (sk2->sk_state == TCP_TIME_WAIT)
+				break;
+			return -EADDRNOTAVAIL;
 		}
+		return 0;
 	}
-	tw = NULL;
 
-	/* And established part... */
+	lock = inet_ehash_lockp(hinfo, hash);
+	spin_lock(lock);
+
 	sk_nulls_for_each(sk2, node, &head->chain) {
 		if (sk2->sk_hash != hash)
 			continue;
-		if (likely(INET6_MATCH(sk2, net, saddr, daddr, ports, dif)))
+
+		if (likely(inet6_match(net, sk2, saddr, daddr, ports,
+				       dif, sdif))) {
+			if (sk2->sk_state == TCP_TIME_WAIT) {
+				tw = inet_twsk(sk2);
+				if (tcp_twsk_unique(sk, sk2, twp))
+					break;
+			}
 			goto not_unique;
+		}
 	}
 
-unique:
 	/* Must record num and sport now. Otherwise we will see
-	 * in hash table socket with a funny identity. */
+	 * in hash table socket with a funny identity.
+	 */
 	inet->inet_num = lport;
 	inet->inet_sport = htons(lport);
 	sk->sk_hash = hash;
 	WARN_ON(!sk_unhashed(sk));
 	__sk_nulls_add_node_rcu(sk, &head->chain);
 	if (tw) {
-		twrefcnt = inet_twsk_unhash(tw);
-		NET_INC_STATS_BH(net, LINUX_MIB_TIMEWAITRECYCLED);
+		sk_nulls_del_node_init_rcu((struct sock *)tw);
+		__NET_INC_STATS(net, LINUX_MIB_TIMEWAITRECYCLED);
 	}
 	spin_unlock(lock);
-	if (twrefcnt)
-		inet_twsk_put(tw);
 	sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 
 	if (twp) {
 		*twp = tw;
 	} else if (tw) {
 		/* Silly. Should hash-dance instead... */
-		inet_twsk_deschedule(tw, death_row);
-
-		inet_twsk_put(tw);
+		inet_twsk_deschedule_put(tw);
 	}
 	return 0;
 
@@ -309,20 +340,31 @@ not_unique:
 	return -EADDRNOTAVAIL;
 }
 
-static inline u32 inet6_sk_port_offset(const struct sock *sk)
+static u64 inet6_sk_port_offset(const struct sock *sk)
 {
 	const struct inet_sock *inet = inet_sk(sk);
-	const struct ipv6_pinfo *np = inet6_sk(sk);
-	return secure_ipv6_port_ephemeral(np->rcv_saddr.s6_addr32,
-					  np->daddr.s6_addr32,
+
+	return secure_ipv6_port_ephemeral(sk->sk_v6_rcv_saddr.s6_addr32,
+					  sk->sk_v6_daddr.s6_addr32,
 					  inet->inet_dport);
 }
 
 int inet6_hash_connect(struct inet_timewait_death_row *death_row,
 		       struct sock *sk)
 {
-	return __inet_hash_connect(death_row, sk, inet6_sk_port_offset(sk),
-			__inet6_check_established, __inet6_hash);
-}
+	const struct in6_addr *daddr = &sk->sk_v6_rcv_saddr;
+	const struct in6_addr *saddr = &sk->sk_v6_daddr;
+	const struct inet_sock *inet = inet_sk(sk);
+	const struct net *net = sock_net(sk);
+	u64 port_offset = 0;
+	u32 hash_port0;
+
+	if (!inet_sk(sk)->inet_num)
+		port_offset = inet6_sk_port_offset(sk);
 
+	hash_port0 = inet6_ehashfn(net, daddr, 0, saddr, inet->inet_dport);
+
+	return __inet_hash_connect(death_row, sk, port_offset, hash_port0,
+				   __inet6_check_established);
+}
 EXPORT_SYMBOL_GPL(inet6_hash_connect);